Sewing machine



H. F. GRU MAN July 12, 1932.

SEWING MACHINE Filed'May s, 1928 5 Sheets-Sheet 1' H. F. GRUMAN Jilly 12, 1932.

SEWING MACHINE Filed May 3, 1928 I5 Sheets-Sheet 2 Home as f. GRuMA/Y,

H. F; GRUMAN SEWING MACHINE July 12,, 1932.

I 3 Sfieets-Sheet 3 Filed May 3, 1928 provements over my co-pending application Patented July 12, 1932 UNITED STATES MACHINE co'MrANY. or. KrrTEnY,

V I snwme Application filed May 3,

This invention relates to new and useful improvements in sewing machines especial ly adapted for joining two body fabrlcs by a French seam, and embodies certain im-.

Serial No. 238,793, filed Dec. 9, 19:27.

Among the several objects of my inven-. tion are to improve the work presenting mechanism of the second or rear seam forming mechanism, and to provide such a mechanism which is simple in construction and is positive in operation. With these and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the description, the appended claims, and the several views illustrated in the accompanying drawings.

In the drawings Figure 1 is a perspective view showing both the front and rear seam forming mech-I anisms of my invention, the horizontal presser foot and associated parts being separated to better disclose the mechanism thereunder, Figure 2 is a vertical transverse sectional view taken through my machine and taken on the line 2 2 of Figure 1,

Figure 3 is a perspective view of the, feed rocker for imparting backand forth move-' ments to the horizontal'feed dog, the view also showing a rocker for imparting back and forth movements to the front Vertical feed dog,

Figure 4 is a perspective view similar to Figure 1 but illustrating another embodi ment of my invention, v

Figure 5 is a perspective view illustrating the steps performed by my invention 1n oining two fabrics by a French seam,

Figure 6 is a detail view of the ridge forniing finger, and i Figure 7 is a perspective view of the French seam formed by my invention.

Like reference numerals designate corresponding parts throughout the several figures of the drawings; V

' Inthe accompanying drawings, I have disclosed only enough of a sewing machine as is necessary for a clear understanding of my invention. The machine is of the flat PATENT v OF CE] HGRACE F. GRUMAN, OF ST. LOUIS, MISSOURI, ASSIGNOR T0 LEWIS INVISIBLE-STITCH ,7.

MAINE, A 'oonrona'rronon 'MAINE- MACHINE i I 1923. Serial; No. 274,584.

bed type and includes a base and jour naled'in a suitable bearing on thisbaseis arotary shaft 6. V p p I The first seam fowm'ng mechanism tal 'plane across the line offeed, and a co.-. .7

operating i-motionthreaded loopery8 for forming a line of Grover & ,Baker stitches. The needle 'Z is attached to a needle ban9. The. specific means for operating thelooper 8 need-not be described as the same is fully described and illustratedgin my cor-pending. application referred to above,

Th work presenting mechanism includes a vertical needle'plate orjguide 10, a vcr tical'e-motion feed dog 11 which operates through an opening in said plate, and aver.- tical presserfoot 12 which cooperates with the plate 10 and dog 11 to feed downwardly extending marginal portions wand 22 of the body fabricsA and B rearwardly past said stitch forming mechanism ,so as to join said portions by a line of stitches c. This stitch forming mechanism, and ,also this work presenting mechanism, is disposed entirely be? lowthe general plane containing the bodyfabrics A and 13.. i

The trimming mechanism Cooperating with the lower .face needle plate 10 is a trimmer blade 13 which oscillatesin a horizontal planebelow the line of'stit'ches 0 to trim the edges of the downtu'rned marginal portions aand bof,

the body fabrics, I The blade 13 is secured to a vertically disposed rockshaft 14 which is oscillated by any suitable mechanism. This trimming mechanism is substantially identi cal'with that disclosed in my co-pending-application referred to above and therefore a further description thereof is thought to be unnecessary.

The second seam forming mechanism The second seam forming mechanism is disposed in rear of the first seam forming mechanism and includes an upper stitch forming mechanism which is entirely disposed above the general plane of the body fabrics, and a cooperating upper work presenting mechanism.

, The upper stitch forming mechanismis the same as is disclosed inmy co-pending application and includes areciprocatory needle 15 which is fulcrumed directly above the seam the body fabrics is a stationary presser foot 17 which is provided on its under face with a guide groove or channel 18 which receives the ridge (Z as it is formed by the ridge forming finger 16. This groove 18 is formed in a' boss 19 which extends'upwardlyfrom the presser foot or plate 17 and includes spaced vertical walls ,2 '21 and a top wall 22. The wall 21 and the top 22 are cut away intermediate the frontand rear ends, and the rear or exposed portion of the wall 20 constitutes a vertical needle or guide plate 20 Supported on the stationary presser foot or plate 17 is a vertical foot 23 which cooperates with the vertical needle plate 20* to clamp the ridge (1 of fabrics therebetween A vertical 4-motion feed dog 24 projects through an opening in the needle plate 2O forcooperation with the vertical presser foot 23 to feed the ridge (Z of the fabrics past the upper and rear stitch forming mechanisms, the needle 15 passing through suitable alined openings formedin the presser foot, 23, the needle plate 20, and vertical feed dog 24. The means for imparting four motions to the vertical feed dog24 are fully described in my co-pending application. f

Cooperating with the presser foot to feed the body. fabrics rearwardly is a horizontal l -motion feed dog 25 which includes a plurality of spaced feedsections 25*. a This feed dog is fixedly mounted on a feed bar 26 having its rear end pivoted as at 27 to the upper end of the feed rocker 28, said rocker being pivotally mounted at its lower end as at 29 to the base 5. p A link 30 has one end pivotally connected to the feed rocker 28 and the other end engaged with the eccentric fixed on the shaft '6. Thus upon rotation of the shaft 6 the feed rocker will impart backward and forward movement to the horizontal feed dog. In order to move the feed dog up and down, I have fixed an eccentric 31 on the shaft 6 and cooperating with the eccentric is a slide 32 which is slidably mounted in an opening 33 formed in a block 34 which is pivoted to the feed rocker 28 by the upper pivot 27 thereof. It will thus be seen that when the shaft 6 is rotated the eccentric 31 will raise the block 34 up and down and said block will also swing about the pivot 27. Disposed between the block 34 and the feed bar 26 is a coil spring 35 which tends to yieldably compress the fabricsagainst the horizontal foot when the block 34 is raised.

Disposed below the horizontal presser foot 17 is a vertically reciprocatory work clamp 36 whichcooperates with said foot to clamp the fabrics against the thrust of the upper needle 15 during successive idle movements of the feed. This work clamp is fixed 'to the upper end of a vertically disposed support 37 whichis mounted for reciprocations in suitable guides mounted on the base 5. Disposed between the base 5 and the support 37 is a spring 38 which functions to yieldably retain the work clamp 36 in cooperative clamping relation with the horizontal presser foot 17. It is desirable to positively lower the work clamp 36 during each feed-' movement of the feed dog 25 and for pess the support 37 against the tension of the. spring 38, thereby 'moving the work clamp downwardly and out of cooperative clamping relation with thehorizontal presserfoot 17.

The ridge forming element or linger 16 is fixed to the front end of a lever 43 which extends longitudinally of the feed bar 26 and is pivotally connected as at 44 by a trans verse pivot to a depending ear 45 integral with the feed bar. The finger 16 projects upwardlythrough an opening 46 formed in the central feed section 25 and also through an open ng formed in the'work clamp 36, and

. the feed sections 25 0 crate throiwli slots 47 p so formed in the work clamp 36.

The rear end of the lever 43 is formed with a cam slot 48 whose major axis is normally inclined upwardly and rearwardly. A stationary pin 49 fixed to the base 5 in any suitable manner, is disposed in the slot 48. Thus when the feed bar 26 is raised and lowered, the

pivot 44. will be correspondingly moved and consequently the lever-43 will swing about the pin 49 and thereby raise and lowerthe ridge forming finger 16. The movement of thefin ger 16 will be considerably increased-or multiplied over the up and down movement of the feed bar, by reason of the lever being pivoted on the feed bar and having the pin and cam slot connection 48, i9. As a result, the-upper needle 15 will pass through the inner'marginal portions e and 7 below the trimmed edges of the outer marginal portions a and b to thereby join the innermarginal portions by a line of stitches g as shown in Figure '7.

In Figure 4, I have shown a slightly modified form of means for supporting and 'oper ating the ridge-forming finger 16. The finger 16 is fixed to a rock arm 50 which'is rigidly connected to a rock shaft 51 journaled in bearings 52, 52 mounted onthe base 5. An actuating rock arm 53 is fixed to the rock shaft 51 andeXtends in a direction opposite the rock arm 50. An eccentric'54 is fixed on the rotary shaft 6 and the arm 53 is retained in constant engagement'with the eccentric by a spring 55. It will be observed that the finger 16 is not supported on the feed bar, but that the rock arms 50', 53 and rock shaft 51 constitute a lever which is fulcrumed on an axis transverse to the line of feed.that the fin er is mounted on one end of the lever, and that means cooperate with the other end of the lever for rocking the same tofreciprocate the finger vertically.

From the foregoing'it will be observed that the body fabrics A and B are normally dis: posed in a horizontal plane and at the beginning of the operationthe adjacent marginal edge portions 00 and b are turned downwardly into side by side relation and fed rearwardly past the needle 7 ofthe front stitch forming mechanism. After thestitches 0 have thus been formed the lower edges of the marginal portions a and b aretrimmed by the trimmer 13. Immediately following the trimming operation the body fabrics together with the previously formed and trimmed seam are projected upwardly to form the ridge d. The ridge d is then fed rearwardly by the "cooperation of the vertical-presser foot 23 and the cooperating vertical feed dog 24 past the rear stitch forming mechanism. Duringthis movement of the fabrics. the body fabrics on opposite sides of the ridge cl are .fed rear wardly through the cooperation of the horizontal presser foot 19 and the horizontal feed dog 26. The Work clamp 36 is reciprocated vertically in timed relation with the horizontal feed dog 26 whereby the clamp" functions whereby the clamp will be loweredduring the feed stroke of the horizontal feed dog to theridge forming finger is pivoted-to move with the horizontal feed dog, and that means are provided for oscillatingsaid fingeridun ing each cycle whereby the ridgerallis constantly being formed during the feeding of the fabrics through the machine. 4

Having thus described the invention, what isclaimedis:

'"1. In a sewing machine for formingFrenchseams, the combination with'front and rear stitch forming mechanisms, one of said mechanisms operating entirely below the general plane of the fabrics to be seamed and the other operating entirely above: the general plane of said fabrics, 1 means for directing vertical edge portions of fabrics into position for seaming by'the front stitchv forming mechanism, a trimming mechanism operating in front of the rear stitch forming mechanism for trimming the edge'portions of the seamed fabrics, means located in rear of the trimming mechanism for projecting a ridge of thefab- V stitch. forming mechanisms'respectively operating'entirely below and entirely above the general plane of. the fabricsfto' be seamed,

means for directing downwardly extending edge portions of fabrics into. position for seaming by the front stitch forming mechanism, means for projectinga ridge of the fabrics including the formed seam" into positionfor seamingfbythe rear stitch forming mechanism, and meansfor directing the ridge of fabrics-into positionfor seaming by the rear stitch forming mechanism comprising a vertical-presser'foot anda'cooperating vere ti'cal feed dog respectively disposed onoppo site sides'of the ridge and cooperating there'- with, a horizontal presser foot disposed above the general plane of the fabrics and provided 7 with an opening through whichfthe ridgeofk fabrics projects, and a horizontal 4-motion' feed dogdisposed'below the general-plane of the-fabricsv'and' cooperatinglwith the horizontal presser foot.-

-3.- In a sewingimachine for forming French 56211115 13118 combination with front and "rear stitch forming mechanisms, oneof said meta; anism's operating entirely below thegeneral plane of the fabrics to be seamedand the otheroperating entirely above the general plane of saidl fabrics, 'inean's for directing vertical edge portions of fabrics into position for seaming by the front stitch forming mechanism,'a trimming mechanism operating in front of the rear stitch forming mechanism for trimming the edge portions of the seamed fabrics, means located in rear of the trimming mechanism for projecting a ridge of the fabrics including the trimmed'seam into position for seamingby the rear stitch 'rear stitch forming mechanism, said ridge forming means comprising a vertically'reciprocatory finger supported for bodily movements with the horizontal feed dog.

7 4. In a sewing machine for forming French seams, the combination with front and rear stitch forming mechanisms, one of said mechanisms operating entirely below the general plane of the fabrics to be jseamed and the other operating entirely above the general plane of said fabrics, a'vertical presser foot located at one side of the vertical edge portions of the fabrics, a vertical feed dog located at the other side of said vertical edge portions and cooperating with the foot to feed the fabrics past the front stitch forming mechanism, meansfor projecting a ridge of the fabricsincluding the formed seam into position for seaming by the rear stitch forming mechanism, and a horizontal presser foot and a horizontal feed dog located in rear of the front stitch forming-mechanism and respectively disposed above and below the seamed fabrics to feed the same past the projecting means and'the rear stitch forming mechanism, the horizontal foot beingyprovided with a recess for receiving the ridge.

5. In a sewing machine for forming French seams, the'combinationwith front and rear stitch forming mechanisms each including a reciprocatory needle, one vof said mechanisms operating entirely below the general plane of the fabrics to be seamed and the other operating entirely above the general planeoi' said fabrics, means for directing vertical edge portions of fabrics into position for seaming by the front stitch forming mechanism, a horizontal'presser foot arranged in rear, of

the front stitch forming mechanism' and through the clamp and foot to project a ridge of the seamed fabrics into position to be seamed by the rear stitch forming mechanism, and a horizontal feed dog operating through the clamp and cooperating With the horizontal presser foot to feed the seamed fabrics past the ridge forming element and the rear stitch forming mechanism. f

6. In a sewing machine for forming French seams, the combination with front and rear stitch forming mechanisms each including a reciprocatory needle, one of said mechanisms operating entirely below the general plane of the fabrics to be seamed andthe other operating entirely above the general plane of said fabrics, a vertical presser foot located at one side of the vertical edge portions of the fabrics, a vertical feed dog located at the other side of said vertical edge portions and cooperating with the foot to feed the fabrics past the front stitch forming mechanism, a horizontal presser foot arranged in rear of the front stitch forming mechanism and above the seamed 'fabricspa vertically movable work clamp disposed below the seamed fabrics and cooperating with the horizontal presser foot to retain the fabrics against movement during the penetrating stroke of the needle of the rear stitch forming mechanism a ridge forming element operating through the clamp and foot to project a ridge ofthe seamed fabrics into position to be seamed by the rear stitch forming mechanism, and a feeddogoperating-through the clamp and cooperating with the horizontal presser foot to feed the seamed fabrics past the ridge forming element andthe rear stitch forming mechanism.

7 In a sewing machine for forming French seams, the combination with front and rear' stitch forming mechanisms, one of said mechanisms operating entirely below the general plane of the fabrics to be seamed and the other operating entirely above thegeneral plane of said fabricsyand work presenting mechanisms for successively presenting vertical edge portions of fabricsto said stitch forming mechanisms, one only of said work presenting mechanismsincluding a stationary horizontal'presser foot and a cooperating horizontal'4-motion feed'dog, and each work presentingmechanism including a vertical presser foot and a cooperating vertical 4-mo tion feed dog." 5

, 8. In a sewing machine for forming French horizontal presser foot and a cooperating horizontal 4-.motion feed dog.

9. In a sewing machine for rorming French, seams, the combination with front and, rear stitch forming mechanisms, one of said me'ch: anisms operating entirely below the general plane of the fabrics to be'seamedand the other operating entirely above the general plane of said fabrics, and work presenting mechanisms for successively presenting vert'r. cal edge portionsof fabrics to said. stitch forming mechanisms, each work presenting mechanism including a vertical feed dog and a cooperating vertical foot, and the rearworlr presenting mechanism including .a horizontal stationary presserifoot and a cooperai'ing horizontal rniotionfecd dog.

10, In a sewing machine for forming French seams, the, combination with front and rear stitch forming mechanisms, one of said mechanisms operating entirely below the general planeof the fabric to be seamed and the other operating entirely above the general plane of. said fabrics, and work pro.- senting mechanisms for successively present.- ing vertical edge portions of fabrics to said stitch forming mechanisms, each work presenting mechanism including a vertical feed dog and a cooperating vertical foot, and the rear work presenting mechanism including a horizontal stationary presser foot, a verti: cally reciprocable work clamp cooperating with the horizontal foot, and ahorizontal trmotion feed dog operating through the work clamp and cooperating with the foot. 7

11. In a sewing machine for forming French seams, the combination with front and rear stitch forming mechanisms, one of said mechanisms operating entirely below the general plane of the ta-brics to be sea-med and the other operating entirely above the general plane of said fabrics, and work presenting mechanisms for successively presenting vertical edge portions of fabrics to said stitch forming mechanisms, each work pre senting mechanism including a vertical teed dog and a cooperating vertical foot,and the rear work presenting mechanism including a horizontal stationary presser foot, a vertically reciprocable work clamp cooperating with the horizontal foot, a horizontal .-inotion feed dog operating through the. work clamp and cooperating; with the foot, gnea-ns for yleldingly retaining the work clamp-against the horizontal foot, a rotary shaft, ameans operated by the shaft for imparting backward and torward movements to the horizontal feed dog, an eccentric iixed to said shaft, and means operatedby said eccentric for raising the horizontal teed dog andtor moving the wo cl mp dow wa d y away rom ooper t on w h the h izo t l; oot

during f d ng mov me zf th d 12- n a s w ng mach ne for formin French seams, the combination with front .andithe otheroperating I general plane of said ta ri'cs 5 and work pre-i and rear stitch .forming mechanisms, one of ing a horizontal stationary presser toot, a

vertically reciprocable work clamp cgoperat':

ing with the horizontal foot, a vertically movable frame to which the work clamp is fixedly connected, a spring for normally retaining the clamp in yielding engagement Withthe horizontal toot, a rotary shaft,and

means for moving the clamp downwardly 1 away from the operative; engagement with the foot including an. eccentric fixed to the shaft,and a lever havingoperative connec: tionwith the frame and the eccentric, and

a horizontal ,lsmotion feed dog operating through the .work clamp and cooperating withthe foot. i

.13. In .a sewing machine ior forming French seams, the combination with trout and rear stitch formlngmechanisms one of said mechanisms operating entirely below the general plane of the fabrics to be seamed and the other operating entirely above the general plane of said fabrics, and work presenting mechanisms for successively presenting vertical edge portions of fabrics to said stitch forming mechanisms, each work presenting mechanism including a vertical feed dog and a cooperating vertical foot and the rear work 5 I presenting'mechanism including a horizon tal stationary presser toot,a vertically'vres ciprocable work clamp cooperating with the horizontal toot, a vertically movable frame to which the'work clamp is fixedly connected and which is provided with aishoul der, a

spring for normally retaining the clamp in yielding engagement with the horizontal foot, a rotary shaft, and means for moving the clamp downwardly away from operative engagement with the toot-including an .eccentric fixed to the shaft, and alev'er ing one end (disposed above arid .operatively connected to the eccentric and having tlie' other end above and incontact with the shoulderion the frammthe tnlcrum oft'he lever being located intermediate the frame and y the eccentric, and a horizontal ii mot'ion feed dog operating through the workclamp and cooperating with the foot. I

:ll. In a sewing machine for itorming French'gseams, the combination with front and rear stitch iorming mechanisms, oneof said mechanisms operating. entirely below the general plane of the tarbricsto he seemed entirely above the s'enting mechanisms for successively presentlng vertical edge portions of fabrics to said stitch forming mechanlsms, one of said work presenting mechanisms including a stationary horizontal presser foot and a 00- operating horizontal Jr-motion feed dog, means for imparting back andforth movements to said dog including a rotary shaft, a feed rocker actuated from said shaft, and a feed bar pivotally connected to the rocker and supporting the feed dog, and means for imparting up and down-movements to the feed dog comprising a frame pivoted to the feed rocker and extending under the feed bar, a spring interposed between the frame and the feed bar, a block slidably mounted in the frame, and an eccentric fixed to the shaft and engaging the block to slide the latter relative to the frame.

15. In a sewing machine for forming French seams, the combination with front and rear stitchgforming mechanisms, one of said mechanisms operating entirely below the general plane of the fabrics to be seamed and the other operating entirely above the general plane of said fabrics; and front and rearwork presenting mechanisms for successively presenting vertical edge. portions of fabrics to said stitch forming mechanisms, the rear work presenting mechanism including a stationary horizontal presser foot and a. cooperating horizontal t-motion feed dog, and each work presenting mechanism including a vertical presser foot and a cooperating vertical Q-motion feed dog, means for imparting back and forth movements to the horizontal feed dog and to the vertical feed dog of the front work presenting mechanism including a'rotary shaft, a feed rocker-actuated from said shaft, and feed bars pivotally' connected to the rocker and respectively supporting the horizontal feed dog and the front vertical feed dog, and means for imparting up and down movements to the horizontal feed'dog comprising a frame pivoted to the feed rocker and extending under-the feed bar to which the horizontal feed dog is connected, aspring interposed between the frame and the lastmentioned feed bar, a block-slidably-mounted in the frame, and an eccentric-fixedto the shaft-and engaging the block to slide the latter relative to the frame. t 16. In a sewing machine o for forming French seams,-:the combination with front and, rear stitch forming mechanisms,one' of said mechanisms operating entirely below the general plane of the fabrics to be seamed and the other operatingaientirely above the general plane of said fabrics; and front and rear work presenting: mechanisms for succ essively presenting vertical edge portions of-rufabrics to said stitch forming mechanisms, the rear work presenting mechanism including a :stationary horizontal presser foot and a cooperating horizontal t-motion feed dog and each work presenting mecha'-' nism including a vertical presser foot and a cooperating vertical t-motion feed dog, means for imparting back and forth move ments to thehorizontal feed dog and to the vertical feed'dog ofthe front work present ing mechanism including a rotary shaft, a feed rocker actuated from said shaft, and feed bars pivotally connected to the rocker and respectively supporting the horizontal feed dog and the front vertical feed dog, and means for imparting up and down movements to the horizontal feed dog and lateral reciprocatory movements to said front vertical feeddog. 1 a

17, In a sewing machine, a work presenting mechanism including a horizontal 4-motion feed dog, and a vertically recipr'oca'tory ridge forming element supported forbodily movements therewith.

18. In a sewing machine, a work presenting mechanism including a horizontal 4-mo-' tion feed dog, a feed barsupporting said dog, and a vertically reciprocatory ridge forming element fulcrumed on the bar for bodily movements therewith.- i

19. In a sewing machine, a work presenting mechanism including a horizontal 4-motion feed dog, a feed bar supportingsaid dog, means for imparting upand down and backward and forward movements to the bar, a lever extending longitudinally of the feed bar and fulcrumed intermediate its ends thereon, a ridge forming element fixedly connected to onev end of the lever, and means cooperating with the other-end of said lever for vertically reciprocating'the ridge forming element during the up and down movements of the feed bar.

20. In a sewing machine, a work presenting mechanism-including a horizontal a-motion feed dog, a feed bar supporting-said dog, means for imparting up and down and backward and forward movements to the bar, a lever extending longitudinally of the feed bar and fulcrumed intermediate its ends thereon, a ridge forming element fixedly connected to one end of the lever, and means cooperating with the other end of said lever for vertically reciprocating the ridge forming element during the up and down'movements of the feed bar, said means comprising a cam slot formed in theend of the lever, and a stationary pin cooperating withsaid cam .slot. v

21. In a sewing machine, a work presenting mechanism including a'horizontal 4-motion feed dog, a feed bar supporting said dog, means for imparting up and down and backward and forward movements-'to'the bar, a ridge forming element fulcrumed on the bar for vertical reciprocations, and means for reciprocatingsaid ridge forming elemen't'a greater distance than theup a'nd down movements of-t'he feed dog.

V the feed do 22. In a feeding mechanism for sewing machines, the combination of a horizontal -motion feed dog, and means for imparting back and forth movements to said dog including a rotary shaft, a feed rocker actuated from said shaft, and a feed bar pivotally connected to the rocker and supporting and means for imparting up and down movements to the-feed dog comprising a frame pivoted to the feed rocker and extending under the feed bar, a spring interposed between the frame and the feed bar, a block slidahly mounted in the frame, and an eccentric fixed to the shaft and engaging the block to slide the latter relative to the frame. I I

In testimony whereof I affix my signature this 17th day of February, 1928.'

HORACE F, GRUMAN. 

